An older spelling of sophomore was sophimore, and it is believed that this resulted from sophism plus the suffix -or, “one who practiced sophism,” which is the art of argumentation, especially on a fallacious premise.
The present spelling stems from the theory that a second-year college student, having acquired some measure of erudition, tends to exploit this knowledge to a degree far beyond its actual worth.
In so doing he is wise (Greek sophos) to the point of folly (Greek, moron), that is, he is a wise fool, sophomoron, or, in Anglicized form, a sophomore.
